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Mansfield RW, Evans MC. EPR Characteristics of the Electron Acceptors A0, A1, and (Fe-S)X in Digitonin and Triton X-100 Solubilized Pea Photosystem I. Isr J Chem 2013. [DOI: 10.1002/ijch.198800018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Agalarov R, Byrdin M, Rappaport F, Shen G, Bryant DA, van der Est A, Golbeck JH. Removal of the PsaF Polypeptide Biases Electron Transfer in Favor of the PsaB Branch of Cofactors in Triton X-100 Photosystem I Complexes fromSynechococcussp. PCC 7002†. Photochem Photobiol 2008; 84:1371-80. [DOI: 10.1111/j.1751-1097.2008.00457.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Hauska G. Transmembrane charge separation within the large subunit of photosystem I-reaction centers from chloroplasts. FEBS Lett 2001. [DOI: 10.1016/0014-5793(80)80259-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Bonnerjea J, Evans M. Identification of multiple components in the intermediary electron carrier complex of photosystem I. FEBS Lett 2001. [DOI: 10.1016/0014-5793(82)80831-4] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Boudreaux B, MacMillan F, Teutloff C, Agalarov R, Gu F, Grimaldi S, Bittl R, Brettel K, Redding K. Mutations in both sides of the photosystem I reaction center identify the phylloquinone observed by electron paramagnetic resonance spectroscopy. J Biol Chem 2001; 276:37299-306. [PMID: 11489879 DOI: 10.1074/jbc.m102327200] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The core of photosystem I (PS1) is composed of the two related integral membrane polypeptides, PsaA and PsaB, which bind two symmetrical branches of cofactors, each consisting of two chlorophylls and a phylloquinone, that potentially link the primary electron donor and the tertiary acceptor. In an effort to identify amino acid residues near the phylloquinone binding sites, all tryptophans and histidines that are conserved between PsaA and PsaB in the region of the 10th and 11th transmembrane alpha-helices were mutated in Chlamydomonas reinhardtii. The mutant PS1 reaction centers appear to assemble normally and possess photochemical activity. An electron paramagnetic resonance (EPR) signal attributed to the phylloquinone anion radical (A(1)(-)) can be observed either transiently or after illumination of reaction centers with pre-reduced iron-sulfur clusters. Mutation of PsaA-Trp(693) to Phe resulted in an inability to photo-accumulate A(1)(-), whereas mutation of the analogous tryptophan in PsaB (PsaB-Trp(673)) did not produce this effect. The PsaA-W693F mutation also produced spectral changes in the time-resolved EPR spectrum of the P(700)(+) A(1)(-) radical pair, whereas the analogous mutation in PsaB had no observable effect. These observations indicate that the A(1)(-) phylloquinone radical observed by EPR occupies the phylloquinone-binding site containing PsaA-Trp(693). However, mutation of either tryptophan accelerated charge recombination from the terminal Fe-S clusters.
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Affiliation(s)
- B Boudreaux
- Department of Chemistry, University of Alabama, Tuscaloosa, Alabama 35487, USA
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Klughammer C, Klughammer B, Pace R. Deuteration effects on the in vivo EPR spectrum of the reduced secondary photosystem I electron acceptor A1 in cyanobacteria. Biochemistry 1999; 38:3726-32. [PMID: 10090761 DOI: 10.1021/bi982431o] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The photoreduction of the secondary PSI electron acceptor A1 in vivo has recently been detected via X-band EPR spectroscopy in intact spinach chloroplasts and in marine cyanobacteria Synechococcus PCC 7002 [Klughammer, C., and Pace, R. J. (1997) Biochim. Biophys. Acta 1318, 133-144]. A further study of the A1- EPR spectrum of Synechococcus PCC 7002 at room temperature with higher-field resolution revealed partially resolved hyperfine structure which was dominated by 0.4 mT splittings of three equivalent protons. The hyperfine splitting was not significantly affected by incubation of the cyanobacteria in 2H2O medium for 20 h, but was absent in fully deuterated cyanobacteria that were grown in 2H2O medium. Anisotropic g-factors consistent with a phylloquinone radical were derived by spectra simulation. Biosynthetic protonation of quinones via the CH3 donor L-methionine in deuterated cells maintained hyperfine structure in the A1- spectrum, indicating the incorporation of CH3 groups in 60% of the deuterated, photoactive A1 molecules. Conversely, biosynthetic quinone deuteration via L-[methyl-d3]methionine in protonated cells led to the loss of the 0. 4 mT splittings in 54% of the A1 molecules. These observations confirm the conclusion of Heathcote et al. [(1996) Biochemistry 35, 6644-6650] of the identity of EPR-detected, photoreduced A1- in vivo with a phylloquinone (vitamin K1) radical in PSI. The partially resolved hyperfine structure of the A1- spectrum indicates an altered spin distribution in the bound vitamin K1- radical in vivo compared to that of unbound vitamin K1- in vitro.
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Affiliation(s)
- C Klughammer
- Lehrstuhl für Botanik I, Julius-von-Sachs Institut für Biowissenschaften, Universität Würzburg, Julius-von-Sachs Platz 2, D-97082 Würzburg, Germany
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Yang F, Shen G, Schluchter WM, Zybailov BL, Ganago AO, Vassiliev IR, Bryant DA, Golbeck JH. Deletion of the PsaF Polypeptide Modifies the Environment of the Redox-Active Phylloquinone (A1). Evidence for Unidirectionality of Electron Transfer in Photosystem I. J Phys Chem B 1998. [DOI: 10.1021/jp981952i] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Fan Yang
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, and Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Gaozhong Shen
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, and Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Wendy M. Schluchter
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, and Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Boris L. Zybailov
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, and Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Alexander O. Ganago
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, and Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Ilya R. Vassiliev
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, and Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Donald A. Bryant
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, and Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - John H. Golbeck
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, and Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
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Golbeck JH. Structure, function and organization of the Photosystem I reaction center complex. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 895:167-204. [PMID: 3333014 DOI: 10.1016/s0304-4173(87)80002-2] [Citation(s) in RCA: 177] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- J H Golbeck
- Department of Chemistry, Portland State University, OR 97207
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Warden JT, Golbeck JH. Photosystem I charge separation in the absence of centers A and B. II. ESR spectral characterization of center 'X' and correlation with optical signal 'A2'. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 849:25-31. [PMID: 3006766 DOI: 10.1016/0005-2728(86)90092-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The Photosystem I electron acceptor complex was characterized by optical flash photolysis and electron spin resonance (ESR) spectroscopy after treatment of a subchloroplast particle with lithium dodecyl sulfate (LDS). The following properties were observed after 60 s of incubation with 1% LDS followed by rapid freezing. (i) ESR centers A and B were not observed during or after illumination of the sample at 19 K, although the P-700+ radical at g = 2.0026 showed a large, reversible light-minus-dark difference signal. (ii) Center 'X', characterized by g factors of 2.08, 1.88 and 1.78, exhibited reversible photoreduction at 8 K in the absence of reduced centers A and B. (iii) The backreaction kinetics at 8 K between P-700, observed at g = 2.0026, and center X, observed at g = 1.78, was 0.30 s. (iv) The amplitudes of the reversible g = 2.0026 radical observed at 19 K and the 1.2 ms optical 698 nm transient observed at 298 K were diminished to the same extent when treated with 1% LDS at room temperature for periods of 1 and 45 min. We interpret the strict correlation between the properties and lifetimes of the optical P-700+ A2 reaction pair and the ESR P-700+ center X- reaction pair to indicate that signal A2 and center X represent the same iron-sulfur center in Photosystem I.
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Rutherford AW, Heathcote P. Primary photochemistry in photosystem-I. PHOTOSYNTHESIS RESEARCH 1985; 6:295-316. [PMID: 24442951 DOI: 10.1007/bf00054105] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/1984] [Accepted: 01/31/1985] [Indexed: 06/03/2023]
Abstract
In this review, the main research developments that have led to the current simplified picture of photosystem I are presented. This is followed by a discussion of some conflicting reports and unresolved questions in the literature. The following points are made: (1) the evidence is contradictory on whether P700, the primary donor, is a monomer or dimer of chlorophyll although at this time the balacnce of the evidence points towards a monomeric structure for P700 when in the triplet state; (2) there is little evidence that the iron sulfur centers FA and FB act in series as tertiary acceptors and it is as likely that they act in parallel under physiological conditions; (3) a role for FX, probably another iron sulfur centrer, as an obligatory electron carrier in forward electron transfer has not been proven. Some evidence indicates that its reduction could represent a pathway different to that involving FA and FB; (4) the decay of the acceptor 'A2 (-)' as defined by optical spectroscopy corresponds with 700(+) % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOramaaBa% aaleaadaqdaaqaaiaadIfaaaaabeaaaaa!37D1!\[F_{\overline X } \] recombination under some circumstances but under other conditions it probably corresponds with P700(+) A1 (-) recombination; (5) P700(+) A1 (-) recombination as originally observed by optical spectroscopy is probably due to the decay of the P700 triplet state; (6) the acceptor A1 (-) as defined by EPR may be a special semiquinone molecule; (7) A0 is probably a chlorophyll a molecule which acts as the primary acceptor. Recombination of P700(+) A0 (-) gives rise to the P700 triplet state.A working model for electron transfer in photosystem I is presented, its general features are discussed and comparisons with other photosystems are made.
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Affiliation(s)
- A W Rutherford
- Service de Biophysique, Department de Biologie, CEN Saclay, BP2, 91190, Gif sur Yvette, France
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Evidence that the low-potential (−700 mV) electron acceptor (X) in Photosystem I has two iron-sulphur centres. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1984. [DOI: 10.1016/0005-2728(84)90090-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Abstract
Photosynthesis is the conversion of the quantum energy of light into the chemical energy of complex organic molecules and organized cellular structures in plants and in some bacteria. The processes of photosynthesis span the time domain of subpicoseconds to the millennia of slow-growing trees, its study brings together such diverse disciplines as photophysics, biochemistry, botany and ecology. In the last few decades tremendous progress has been made in understanding the multivarious chemical reactions that ultimately lead to the fixation of carbon dioxide into organic substance, yet the basic mechanism underlying the conversion of photon energy into chemical energy still remains very much an enigma. These so-called primary reactions which transduce the excitation energy of excited chlorophyll pigments into the potential energy of stabilized, separated charges on electron donor and electron acceptor molecules have been studied with a variety of physical techniques, among which fast optical spectroscopy and electron paramagnetic resonance (EPR) are prominent. This review will highlight one intriguing aspect of EPR, namely that of electron spin polarization (ESP).† It will be shown that ESP of photosynthetic primary reactants offers a unique tool to gain insight in the electrostatic and magnetic interactions that make photosynthesis work. Moreover, it will become apparent that ESP in photosynthesis has several unique traits not (yet) found in ESP of photochemical reactionsin vitro. As such, it may serve as a paradigma of ESP phenomena and will present an absorbing spectacle also for EPR spectroscopists outside photosynthesis.
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Manikowski H, McIntosh AR, Bolton JR. A study of chemically induced dynamic electron polarization (CIDEP) in Photosystem I of whole algal cells at ambient temperatures. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1984. [DOI: 10.1016/0005-2728(84)90158-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Diazonium modification of Photosystem I. A specific effect on iron-sulfur Center B. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1984. [DOI: 10.1016/0005-2728(84)90141-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Orientation dependence of radical pair interactions in spinach chloroplasts. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1983. [DOI: 10.1016/0005-2728(83)90028-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Gast P, Swarthoff T, Ebskamp F, Hoff A. Evidence for a new early acceptor in Photosystem I of plants. An ESR investigation of reaction center triplet yield and of the reduced intermediary acceptors. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1983. [DOI: 10.1016/0005-2728(83)90170-6] [Citation(s) in RCA: 69] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Primary processes in Photosystem I. Identification and decay kinetics of the P-700 triplet state. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1982. [DOI: 10.1016/0005-2728(82)90174-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Radical pair interactions in spinach chloroplasts. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1982. [DOI: 10.1016/0005-2728(82)90267-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Photooxidation of the Reaction Center Chlorophylls and Structural Properties of Photosynthetic Reaction Centers. ACTA ACUST UNITED AC 1982. [DOI: 10.1007/978-3-642-81795-3_4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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Proton and nitrogen electron nuclear double and triple resonance of the chlorophyll a anion in liquid solution. Chem Phys Lett 1982. [DOI: 10.1016/0009-2614(82)83449-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Flash-induced absorption changes in Photosystem I, Radical pair or triplet state formation? BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1981. [DOI: 10.1016/0005-2728(81)90235-8] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Møller BL, Nugent JHA, Evans MCW. Electron paramagnetic resonance spectrometry of photosystem I mutants in barley. ACTA ACUST UNITED AC 1981. [DOI: 10.1007/bf02907959] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Rutherford AW, Mullet JE. Reaction center triplet states in photosystem I and photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA 1981; 635:225-35. [PMID: 6263331 DOI: 10.1016/0005-2728(81)90022-0] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A photosystem I (PS I) particle has been prepared by lithium dodecyl sulfate digestion which lacks the acceptor X, and iron-sulfur centers B and A. Illumination of these particles at liquid helium temperature results in the appearance of a light-induced spin-polarized triplet signal observed by EPR. This signal is attributed to the triplet state of P-700, the primary donor, formed by recombination of the light induced radical pair P-700+ A1- (where A1 is the intermediate acceptor). Formation of the triplet does not occur if P-700 is oxidized or if A1 is reduced, prior to the illumination. A comparison of the P-700 triplet with that of P-680, the primary donor of Photosystem II, shows several differences. (1) The P-680 triplet is 1.5 mT (15 G) wider than the P-700 triplet. This is reflected by the zero-field splitting parameters, which indicate that P-700 is a slightly larger species than P-680. The zero-field splitting parameters do not indicate that either P-700 or P-680 are dimeric. (2) The P-700 triplet is induced by red and far-red light, while the P-680 triplet is induced only by red light. (3) The temperature dependences of the P-700 triplet and the P-680 triplet are different.
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